A gallery assistant looks at a portrait of Frida Kahlo by Mexican artist Diego Rivera entitled 'Nude with beads' during the press view of the 'Revolution on Paper' exhibition at the British Museum, in London, on October 21, 2009. The display of Mexican prints is the first in Europe focusing on Mexican printmaking in the first half of the twentieth century. Through this period, the country faced socialist revolution with artists promoting the values of the revolution in poster artwork. The exhibition runs from October 22, 2009 to April 5, 2010. AFP PHOTO/Leon Neal (Photo credit should read Leon Neal/AFP/Getty Images)